GYMNOCALYCIUM A COLLECTOR’S GUIDE GYMNOCALYCIUM A Collector’s Guide JOHN PILBEAM Photography by BILL WEIGHTMAN A.A. BALKEMA / ROTTERDAM / BROOKFIELD / 1995 Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by A.A.Balkema. Rotterdam, provided that the base fee of US$1.50 per copy, plus US$0.10 per page is paid directly to Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, USA. For those organizations that have been granted a photocopy license by CCC, a separate system of payment has been arranged. The fee code for users of the Transactional Reporting Service is: 905410 192 X195 US$1.50 + US$0.10. Published by A. A. Balkema, PO. Box 1675, 3000 BR Rotterdam, Netherlands (Fax: +31.10.4135947) A.A. Balkema Publishers, Old Post Road, Brookfield, VT 05036, USA (Fax: 802.276.3837) ISBN 90 5410 192X © 1995 A.A. Balkema, Rotterdam Printed in the Netherlands V Contents Preface VII Acknowledgements XI 1 Cultivation 1 2 Classification 5 3 Seed, fruit, flowers and spines 11 4 Geography and distribution 17 5 Discovery and collection of species in the wild 31 6 Commentary on species 33 7 Checklist of Gymnocalycium species 155 8 Field lists of Gymnocalycium 157 Glossary with particular reference to Gymnocalycium 181 Sources of seed or plants of Gymnocalycium 183 Bibliography 185 Index 187 Preface VII Preface The genus Gymnocalycium has been popular with cactus fanciers for many years. It is widespread in the wild, with most species occurring in northern Argentina and southern Bolivia, and a handful in southern Brazil, south-western and northern Paraguay and Uruguay. New species or variants of species have been discovered steadily since the recognition by Britton and Rose in 1922 of Karl Pfeiffer’s genus Gymnocalycium, proposed by him some 70 years before, and some of the earliest of cactus illustrations are of species of Gymnocalycium, then called under the umbrella name for ribbed, globular cacti, Echinocactus. Britton and Rose recognized 23 species, as follows: G. anisitsii, G. brachyanthum, G. damsii, G. denudatum, G. gibbosum, G. guerkeanum, G. hyptiacanthum, G. joossensia- num, G. kurtzianum, G. leeanum, G. megalothelos, G. melanocarpum, G. mihanovichii, G. monvillei, G. mostii, G. multflorum, G. netrelianum, G. platense, G. saglione, G. schickendantzii, G. spegazzinii, G. stuckertii, G. uruguayense. Backeberg in his monumental work, Die Cactaceae, expanded this considerably, listing 65 species, recognizing 58 of them, and included 27 recognized varieties. They were as follows: G. albispinum, G. andreae (& var. grandflorum), G. anisitsii, G. artigas, G. asterium, G. baldianum, G. bodenbenderianum, G. brachypetalum, G. bruchii, G. calochlorum (& var. proliferum), G. capillaense, G. cardenasianum, G. castellanosii, G. chubutense, G. damsii, G. deeszianum, G. denudatum, G. eytianum, G. fleischerianum, G. gibbosum (& var. leucodictyon, var. nigrum, var. nobile), G. gran- diflorum, G. guerkeanum, G. hossei (& var. longispinum), G. hybopleurum (& var. euchlorum), G. hyptiacanthum (& var. citriflorum), G. joossensianum, G. knebelii, G. lagunillasense, G. leeanum (& var. brevispinum, var. netrelianum), G. leptanthum, G. marquezii, G. marsoneri, G. mazanense (& var. breviflorum, var. ferox), G. megalo- thelos, G. megatae, G. melanocarpum, G. michoga (incl. G. tortuga Hort.), G. mihano- vichii (& var. friedrichii, var. melocactiforme, var. pirarettaense, var. stenogonum), G. monvillei, G. mostii (& var. kurtzianum), G. multiflorum, G. nidulans, G. nigriareolatum (& var. densispinum), G. ochoterenai (& var. cinereum), G. oenanthemum, G. onycha- canthum, G. parvulum, G. pflanzii, G. platense, G. quehlianum (& var. albispinum, var. flavispinum, var. rolfianum, var. zantnerianum), G. ragonesei, G riograndense, G. saglione, G. schickendantzii (& var. delaetii), G. sigelianum, G schroederianum, G. spegazzinii (& var. major), G.stuckertii, G. triacanthum, G. tudae, G. uruguayense, G. valnicekianum, G. vatteri, G. weissianum (& var. atroroseum, var. cinerascens), G. zegarrae; he also listed G. saglione var. tilcarense, but pulled it out of Gymnocalycium into a separate monotypic genus, viz. Brachycalycium tilcarense. Bohumil Schütz of Czechoslovakia in a recent monograph lists over 100 species, with question-marks over some. But the most recent general pronouncement on the make-up of the genus is in the CITES Cactaceae Checklist compiled by David Hunt, VIII Preface consulting three eminent students of this genus for the content on Gymnocalycium, Massimo Meregalli, Detlev Metzing and Geoffrey Swales. They recognize as accepted species 37, and as ‘provisionally accepted’ a further 42. Accepted species are: G. alboareolatum, G. andreae, G. anisitsii, G. baldianum, G. bodenbenderianum, G. bruchii, G. buenekeri, G. calochlorum, G. capillaense, G. cardenasianum, G. castellanosi, G. chiquitanum, G. deeszianum, G. denudatum, G. fleischerianum, G. gibbosum, G. horstii, G. hossei, G. hybopleurum, G. leptanthum, G. marsoneri, G. mesopotarnicum, G. mihanovichii, G. monvillei, G. mostii, G. nigriarola- tum, G. oenanthemum, G. paediophilum (sic!), G. paraguayense, G. pflanzii, G. quehlia- num, G. ragonesei, G. saglionis, G. schickendantzii, G. schroederianum, G. spegazzinii, G. uruguayense. Provisionally accepted species are: G. acorrugatum, G. ambatoense, G. bayrianum, G. bicolor, G. borthii, G. carminanthum, G. erinaceum, G. eurypleurum, G. ferrarii, G. friedrichii, G. glaucum, G. guanchinense, G. horridispinum, G. hyptia- canthum, G. intertextum, G. joossensianum, G. kieslingii, G. leeanum, G. mazanense, G. megalothelon (sic!), G. melanocarpum, G. multjflorum, G. netrelianum, G. obductum, G. occultum, G. ochoteranae (sic!), G. piltziorum, G. platense, G. pungens, G. rauschii, G. riojense, G. ritterianum, G. schatzlianum, G. stellatum (in part), G. striglianum, G. stuckertii, G. taningaense, G. tillianum, G. triacanthum, G. uebelmannianum, G. valnicekianum, G. vatteri. It is worth spelling out the definition of the category ‘provisionally accepted’, which is broad in its application, with no indication as to what category applies to the different species listed. It is as follows: ‘Correct’ names at specific rank (according to current generic usage, where combinations exist) of taxa treated as distinct species in one or more of the secondary sources consulted, or as distinct subspecies (or, exceptionally, varieties) in a primary source, together with names of taxa whose acceptance is disputed or awaits confirmation’. The primary source for Gymnocalycium was Mas- simo Meregalli’s publication ‘Ii genere Gymnocalycium’ published in Piante Grasse 51:5-63 (1985); secondary sources were those mentioned above, and maybe others, e.g. Roberto Kiesling, who is keenly interested in this genus as it occurs in Argentina. Since Britton and Rose’s classic base, The Cactaceae, the genus has been generally acknowledged, and the distinct appearance of the species has caused little confusion with other genera. The naked bud, for which the genus was named, the distinctive form with more or less prominent ‘chins’, as the humps on the ribs have come to be called from the resemblance to a human chin, and the often distinctive spination have few imitators, and most collectors can immediately identify most Gymnocalycium species as of that genus, and recognize the more common of them readily. Some species are very distinct, and can be confused with no other, while others merge in appearance, and are more or less closely related. Several are very variable, and this has led to a proliferation of infraspecific names to point up these differences, often poorly founded with no indication of their origins. Many such names are entirely unnecessary, have fallen by the wayside since their erection, and can largely be ignored. The present most popular classification is based on seed structure, and is not wholly satisfactory, especially from the collector’s point of view, since seed is not available readily, and needs usually at least a × 10 lens to determine the group it belongs to. But it gives a broad basis for groupings, which, together with other characters helps better to understand the species’ relationships and base further study. The similarities in the seeds’ shape and size, which more or less tie in with their geographical distribution have resulted in other schemes of classification, notably by Buxbaum, which has some strong followers, fined down further on body and spine characters – see Chapter 2. Few Preface IX species present any difficulty in cultivation, provided that basic requirements for cactus cultivation are followed, and in some 40 years cactus growing I cannot ever remember losing a Gymnocalycium, except to an acquisitive friend. I hope that this book, intended for use by the enthusiast rather than to be taken too seriously as a monograph, which it is not, will show the collector what the range of species is, and help him identify or verify the plants he acquires, as well as presenting under one cover information scattered hitherto in various publications over a period of many years. In the course of its preparation I have swelled my collection of this genus from a modest 120 plants to over 800, and have travelled extensively to see various collections, or corresponded with enthusiasts in the UK, the USA, Canada, Australia, Germany, Belgium and Czechoslovakia. That Gymnocalyciums are widely popular is in no doubt; if this book helps a little to increase their popularity it will have